In the diagram shown above, the circles represent small balls that have electric charges. Ball 1 has a negative charge, and ball 2 is repelled by ball 1
Next, you see that ball 2 repels ball 3 and that ball 3 attracts ball 4. What is
the electric charge on ball 4?
Ball 4 may have either a positive or negative charge,
Ball 4 has a negative charge.
Ball 4 has a positive charge.

If state law mandates that elevators cannot accelerate more than 2.40 m/s2 or travel faster than 14.8 m/s , what is the minimum time in which an elevator can travel the 373 m from the ground floor to the observatory floor? ?

Acharge q experiences no net force at a particular point in space. which of the following situations described below must always be true? -there are no other charges nearby. -if there are other charges nearby, they must all have the same sign as q. -if there are other charges nearby, they must all have the opposite sign of q. -if there are other charges nearby, the total positive charge must equal the total negative charge. -none of the above

Carmen is load furniture and boxes onto a moving truck. she picks up boxes of her things, places them on a cart, and pushes the cart to the moving van. which term best describes the type of force carmen uses? a. contact b. friction c. gravity d. noncontact